KZN130 Surf sticking in 4wd

[bronx89]

Hi guys,

Been a while - back from overseas and wanting to get this annoying niggly issue sorted in my Surf.

KZN130 1995 Hilux Surf 3.0L TD

4WD hi and low work perfectly ok, however, when I try and go back into RWD from either 4WD hi or low it just won't come out of 4WD. The light stays on and it still feels as though it's in 4WD.

The only way to get it out of 4WD seems to be to stop, turn the truck right off, then turn it back on. This works every time without fail. Although it is very annoying having to stop and turn it off then on everytime I want to switch between 4 and 2 on the beach or anywhere else.

Has anyone else struck this problem before? Or does anyone have any ideas what would be causing this? Wanting to fix it sooner rather than later but unsure what's causing the issue.

Cheers

---

EDIT: Just remembered that before I left I found that in 4wd if I put it in N and turn the key off (truck still runs because of turbo timer) and then push the button if in high range or move lever to high rear if in low range and then turn key back to on it will immediately be out of 4wd too - if that helps anyone.

[mudlva]

Try the reverse back trick
With trans in neutral disengage front output shaft by either push button or selecting hi'box
Then select reverse and move about 3-5 mtrs
If this didn't work try again but give the gas peddle a but if a blip this will normally push the forward output free.
The output has special gears that mesh in thus stopping it from accidentally being disconnected. Sometimes it needs a but of encouragement to disengage

[bronx89]

Hey mate yea have tried that plenty of times and no luck.

Used to work fine when I first got the truck then all of a sudden she just started playing up and not wanting to get out of 4WD without being turned off then on again.

Swapped out the 4WD ECU under the headunit today with a mates identical truck and no change. His worked fine and mine wouldn't.

Also noticed when truck off and ignition on, pressing the hi 4WD/RWD button on his truck you could hear 2 relay clicks as well as the little motor on the gearbox going with each press of the button, with mine you can hear 1 click with the first press of the button and that's it, pressing it again nothing, no gearbox motor sound at all even with the first press. Although the 4WD does actually work when offroad fine :-/ if that all makes sence

[cruiser80]

Our one did it too, I had to swap the vacuum hoses on the two solenoid valves on the drivers side by the battery to get it out of 4wd.

After driving around like that for a few weeks it went fine and never jammed again.

[bronx89]

Hmm ok. Did yours get out of 4WD if you shut the truck off and turned it back on (or if had a turbo timer left it running but turned the key fully to off then back to on)?

If my truck can stay on but the key just needs to be moved to off then on do you have any idea what it would be? Could it be one of those solenoid valves? Do they go directly to the vacuum pump?

One last thing, do you have a picture of the solenoid valves you're talking about? I'll have a look a little later on today and try and find them. Thanks.

[bronx89]

Is this the do-dad you're talking about?



If so, do you think that's likely causing this weird issue? Do you know what in particular would/could be causing it?

[jonossiksilvia]

these should help you sort it

[bronx89]

Very good thanks for those diagrams!

I'm beginning to think it could be the ADD relay behind the speedo cluster - does anyone know if this was the culprit whether or not the 4WD light would still work? Because the 4WD light still works accurately.

Or is anyone able to advise where I should be looking/checking first? Have a marine electrician mate with all the electrical gear to test everything but just unsure where to start as I've ruled out the 4WD ECU under headunit.

[jonossiksilvia]

id also suggest going through your last thread again as more diagrams etc there.

http://www.offroadexpress.co.nz/Forums/ ... 22&t=35133

[bronx89]

Nothing new in there

[cruiser80]

Yes that's the valves I swapped the hoses on.
Ours was a 2.8 and didn't have a turbo.
Turning key off made no difference, nor did moving in and out of low range.
The 4wd light stayed on from memory.

[bronx89]

Ok a bit more info:

Had the truck in P 2HI on flat surface turned on, front drive shaft will NOT spin.

Jacked up each front wheel (one at a time) and both will spin freely.

So the transfer case is staying engaged even when the truck is not in 4WD. The ADD system itself is working correctly as the front differential is disengaged allowing each front wheel to spin freely and independently of the other regardless of the drive shaft.

Does that give anyone enough info to diagnose the fault and a fix?

[nzlux]

Ok a bit more info:

Had the truck in P 2HI on flat surface turned on, front drive shaft will NOT spin.

Jacked up each front wheel (one at a time) and both will spin freely.

So the transfer case is staying engaged even when the truck is not in 4WD. The ADD system itself is working correctly as the front differential is disengaged allowing each front wheel to spin freely and independently of the other regardless of the drive shaft.

Does that give anyone enough info to diagnose the fault and a fix?

I may be wrong but your diff might still be engaged as I understand an open diff will allow one wheel to spin freely even if the drive shaft is engaged.

What happens if you put both front wheels on axle stands, and the gearbox in gear, engine off, can you turn the driveshaft and will it turn the front wheels?

[bronx89]

I tried both wheels one at a time pretty sure it wouldn't switch between the 2 would it?

Anyhow, I'll jack it up again tomorrow morning with both off the ground try and spin each and see what happens with the drive shaft and each wheel. I'm assuming it'll be far too heavy to do it the other way around trying to spin the drive shaft to spin the wheels (if it does spin the wheels)?

Will post up results tomorrow morn.

Anyone else know of what would cause this? Could it be something to do with the electrical/vacuum unit thing on the transfer case that engages and disengages the front drive shaft?

[nzlux]

If the hubs are locked to the axles with both wheels off the ground they might spin in opposite directions (differential working) regardless of whether the drive shaft is locked to them or not.
My LN106 hilux has a beam front axle (and auto locker), with both wheels off the ground and manual hubs locked, transfer case in 2wd in I can turn the front driveshaft by hand and it will spin the wheels.

[Smurf]

If your Surf still has the factory drive plates/flanges, or Free wheeling hubs in LOCK. When you jack one wheel and turn it the driveshaft will spin if the ADD is engaged.

[bronx89]

Jacked up both front wheels off the ground, can spin each wheel freely without the other spinning, and the drive shaft also doesn't spin when each of the front wheels are spun. Cannot spin the drive shaft with both front wheels off the ground either.

So does this mean the ADD is working, and there is something playing up inside the transfer case? And is it safe to drive like this? No risk of f*cking front diff or transfer case or gearbox or anything?

Does anyone know what would cause this particular issue?

[bronx89]

Not sure what it's called but on the side of the transfer case there is a little cap that comes off with 3 10mm bolts that has wires and a vacuum line going to it. I am assuming this is what controls the engaging and disengaging of the front drive shaft?

There is also an allen key bolt underneath with a locking nut. I took the plate off, and it looks like the allen key bolt joins up to a spline that runs along side the gear inside. Is that used to adjust something?

Sanded back the contacts and put some grease in there whilst it was apart.

Also looks like there is a little motor ontop with no plug or anything going to it. Could this be buggered? I remember i used to be able to hear the motor go with each press of the button after the relay clicks. Now just one relay click with on and no motor sound and no relay clicks when trying to go off.

Pls refer to post above this too for more info and Q regarding if it is safe to drive like this without it stuffing diffs or transfer case etc.

Pic below:

[imsohi]

sounds like the electric engage motor on the transfer to me if drive shaft is locked and both wheel spin freely without turning driveshaft then you front diff is disengaged as it should be in 2 HI, try getting some to click the 4wd in and out and get under and have a listen to see if the motor is working.

[bronx89]

sounds like the electric engage motor on the transfer to me if drive shaft is locked and both wheel spin freely without turning driveshaft then you front diff is disengaged as it should be in 2 HI, try getting some to click the 4wd in and out and get under and have a listen to see if the motor is working.

Hi there, the electric motor seems to work fine as you can hear it going when the 4WD button is switched on/off. Once it's been switched to 4WD it just stays in 4WD and won't come out (light won't turn off) unless key is moved to OFF then back to ON (truck stays running due to turbo timer), the 4WD light will then switch off and the truck is in RWD however the front drive shaft stays engaged/locked.

[bronx89]

Anyone?

[jonossiksilvia]

There is enough information in this topic and links posted up on the previous page, let alone this forum and the internet to test everything related to the 4wd system. Go through the correct testing procedures for each part, wiring etc or even swap parts with another known working surf. Failing that take to a 4wd workshop pay the money and it'll work.

[bronx89]

There is enough information in this topic and links posted up on the previous page, let alone this forum and the internet to test everything related to the 4wd system. Go through the correct testing procedures for each part, wiring etc or even swap parts with another known working surf. Failing that take to a 4wd workshop pay the money and it'll work.

If I wanted to take it to a workshop I wouldn't be posting on here. I've tested all the main parts and they're fine I've also swapped them out and it makes no difference to either truck.

I was hoping at least one person would have had (or heard of) this before and would be able to shed some (direct) light on the issue.

[imsohi]

sounds like the electric engage motor on the transfer to me if drive shaft is locked and both wheel spin freely without turning driveshaft then you front diff is disengaged as it should be in 2 HI, try getting some to click the 4wd in and out and get under and have a listen to see if the motor is working.

Hi there, the electric motor seems to work fine as you can hear it going when the 4WD button is switched on/off. Once it's been switched to 4WD it just stays in 4WD and won't come out (light won't turn off) unless key is moved to OFF then back to ON (truck stays running due to turbo timer), the 4WD light will then switch off and the truck is in RWD however the front drive shaft stays engaged/locked.

Front drive shaft or front axels? axels will always be locked if you have the drive flanges and if drive shaft (gearbox to diff) is still engaged (locked) it will be either the electric motor or the vacume engaged parts in the front diff which its sounding like do a search this has been well covered on this forum. i usually take the pipes off and suck on each one to see if its working.

[bronx89]

Front drive shaft or front axels? axels will always be locked if you have the drive flanges and if drive shaft (gearbox to diff) is still engaged (locked) it will be either the electric motor or the vacume engaged parts in the front diff which its sounding like do a search this has been well covered on this forum. i usually take the pipes off and suck on each one to see if its working.

The drive shaft. Standard hubs.

Do you know of any easy way to test the electric motor? As said before I can hear it going so it's not dead but I suppose it could still be faulty.

I'll do a search regarding vacuum faults causing 4wd and front drive shaft issues - although I've done this before and nothing was similar to what mine's doing.

When you say you take the pipes off, are you meaning the vacuum hoses? Which ones do you take off and where abouts? By the VSV's? And when you suck on each one how do you tell if they're working or not - what's supposed to happen?

Thanks

[bronx89]

I believe this is the engage sensor for the front drive shaft on the transfer box?

Is this both how the sensor and inside the hole should look? I did notice watery oil on the sensor (I do a fair bit of water work).

Also tested VSV vacuum lines and both seem fine with no leaks/loss of suction.

[Sheepy]

Sorry to dredge up an old thread, but did you find a fix for this issue. Mine does the same thing as yours does, I haven't had a chance to test everything yet to isolate the issue (known issue before purchase) but I did find a thread on another forum that shows a simple fix for the issue. I'm not sure on the rules of posting links to other forums so I won't post it here, but I searched "how to disengage 4wd in a kzn130 " and a link was posted to a tech article on a UK hilux forum. I will happily post the link if it's allowed. I am going to do this modification to mine, as it appears to be a fix for what seems to be a common issue.

[Smurf]

Sorry to dredge up an old thread, but did you find a fix for this issue. Mine does the same thing as yours does, I haven't had a chance to test everything yet to isolate the issue (known issue before purchase) but I did find a thread on another forum that shows a simple fix for the issue. I'm not sure on the rules of posting links to other forums so I won't post it here, but I searched "how to disengage 4wd in a kzn130 " and a link was posted to a tech article on a UK hilux forum. I will happily post the link if it's allowed. I am going to do this modification to mine, as it appears to be a fix for what seems to be a common issue.

no problems posting up your links to other forums.

[Sheepy]

In that case, this link has a guide on how to fix it for good.

http://www.hiluxsurf.co.uk/showthread.php?t=66755

This is the original link, but the one above has a lot more detailed pics.

http://www.4x4wire.com/toyota/tech/add/

[bronx89]

Hey thanks for the links, yep I've seen that post before but didn't want to have to do that wanted to fix whatever was wrong let me know if it fixes yours once you've done it!